Method of making knife units for meat cutters



061:. 24, 1939. BECKNER 2,176,867

METHOD OF MAKING KNIFE UNITS FOR MEAT CUTTERS Filed Feb.. 24, 1959 1707mm 0.13ec7vne8;

Patented Oct. 24, 1939 UNITED STATES PATENT OFFICE METHOD OF MAKING KNIFE UNITS FOR MEAT CUTTERS 3 Claims.

My present invention relates to plural-bladed rotary knife units, including the knife or cutter proper and an associated die plate, particularly for meat cutters, and aims to provide extremely durable, non-corrosive and otherwise improved units of the character referred to, together with a novel method of making the knife element.

In the drawingillustrating by way of example one embodiment of the invention and certain steps for practicing its method,

Fig. 1 is a section through the delivery end of a meat cutter-having a knife unit of the invention installed therein;

Fig. 2 is a plan of a core, blank or forging for the knife;

Fig. 3 illustrates an early step in the formation of the knife, showing in plan certain stainlesssteel members in position for uniting with the core of Fig. 2;

Fig. 4 is a plan view of the knife of Fig. 3 following an intermediate step in the process;

Fig. 5 shows in plan the knife of Figs. 3 and 4, inverted and further processed into final or substantially complete form;

Figs. 2a, 3a, 4a and 5a are enlarged cross sections respectively on the correspondingly numbered section lines of Figs. 2, 3, 4 and 5;

Fig. 6 is a plan View showing the outer or bottom face (that seen in Figs. 3 and 4) of a finished knife, after grinding and polishing to the extent desired; and

Fig. 6a is an enlarged end view of one arm of said finished knife.

Referring to the drawing in more particular, in Fig. 1 I have represented the delivery end of a typical meat cutter or grinder, including the main head 1 housing the feed screw 8 and having a retaining cap 9 threaded onto its outer edge. The feed screw 8 has an outwardly projecting central shaft ill with a non-circular portion II for receiving the knife, the latter indicated as a whole by the numeral [5. The knife has a central correspondingly shaped aperture fitting said non-circular portion of the shaft, so that the knife is caused to rotate with the feed screw 8.

Outwardly of the knife I5 is a stationary perforate plate or die element l2 of novel construction. Desirably it is composed of a special extremely hard stainless steel, and has formed integrally in one piece with it a central boss I3 apertured to receive and form a bearing for the outer cylindrical portion of the shaft l0. This die plate 12 is clamped in fixed position in the head I, by the threaded cap 9, being held against turning as by a notch 14 at some peripheral portion of the plate engaging a correspondingly shaped projection on the head. The plate has a multiplicity of apertures I2a drilled through it, the meat being forced through the apertures by the feed screw and cut off by the knife rotating across them with its cutting edges contacting the inner or rear face of the plate.

Referring now more particularly to Figs. 2 to 6, and first to Fig. 2, I have there shown in plan a core, blank or forging indicated as a whole by the numeral 16. This element provides in effect a base for the composite knife as a whole. It is forged or otherwise formed from ordinary relatively low-grade steel, such as any good coldrolled steel, having substantial toughness, as contrasted with brittleness, but relatively soft and hence unsatisfactory for the formation of cutting edges which are subject to substantial wear.

Said core comprises a hub I! having a noncircular aperture to conform to the like-shaped portion ll of the meat-cutter shaft l0, Fig. 1. The hub H has formed integrally with it a plurality of lateral arms I8 extending in a generally radial direction, one arm for each of the blades of the knife. Any plurality of blades and arms may be employed, usually at least three, but in most instances I find that four such elements, disposed substantially at right angles to each other, are preferable. The arms l8 may be variously shaped in cross section; see for example Fig. 2a and the other sectional views. Each has one corresponding longitudinal side made approximately straight and flat, as indicated at l9.

Further in accordance with my method this core or forging I6 is positioned substantially flatwise on a welding table, with either face up, that shown in Figs. 2, 3 and 4 being the face corresponding to the outer or front face of the finished knife. As illustrated in Fig. 3, I apply along each of the arms [8, in abutting relation to their flat side faces [9, a rod or bar 20 of a high-grade hard stainless steel. As clearly seen in the corresponding enlarged section, Fig. 3a, these rods are somewhat larger in section than the arms of the core, and have a polygonal or other cross sectional shape, herein rectangular, to provide along at least one longitudinal portion an angular corner section 2| adapted to constitute the cutting edge element for the corresponding finished blade.

With the parts positioned as in Figs. 3 and 3a the material at the upper and inner longitudinal portion of each stainless-steel rod 20, inwardly from the corner sections 2|, is subjected to a fuse Welding operation in the course of which it is flowed over onto and across the then upper face of the adjacent arm I8. During this operation said outer corner portions 2| of the stainless-steel rods 20 are kept intact, in their original condition. The resulting formation, wherein the arms l6 of the core and the juxtaposed stainless-steel elements 20 have been united into embryo blades 22, is illustrated in Fig. 4 and Fig. 4a. In the several sectional views the original shape of the stainless-steel rods is indicated by the dotted lines.

In the further procedure under my method the partly formed knife of Fig. 4 is inverted and positioned on the welding table with its other face upward, as represented in Fig. 5. The then upper longitudinal portions of the stainless-steel rods 26, again excepting the corner portions 2!, are similarly fused and flowed across and about the adjacent portions of the corresponding arms 58, so as substantially to enclose the latter, and outer portions of the hub ll if desired, in a coating of said non-corrosive material; see particularly Fig. 5a.

It will be particularly noted that throughout the fuse welding steps the stainless-steel material along the corner portions 2| of the rods is not touched but remains unchanged from its original condition and shape. Hence with the completion of the operation illustrated in Figs. 5 and 5a the knife l5 as a whole is substantially complete, subject only to such finishing by way of grinding and polishing as may be desirable. Since said corner portions 2| of the stainless-steel rods have not been fused or melted they are entirely free of irregularities such as blow holes which are likely to result from welding. Accordingly they present a uniform surface and edge available as the cutting element for the blades, with but a minimum of grinding or finishing to conform them to the inner face of the die plate l2 with which they are to cooperate.

Fig. 6 illustrates a completed knife, with its outer or front face upward, as in Figs. 2 to 4. The ends of the composite blades 22 may be rounded off as there shown, making them uniform and giving the knife an attractive appearance. The leading edge portions 2! of the several blades 22, provided by the intact corner portions of the stainless-steel rods, are ground to any extent necessary to sharpen their edges and true their front surfaces into a given plane, affording fiat riding faces 23 for moving over and in contact with the die plate E2. The attractive appearance of the knife may be further improved by polishing, giving it a bright surface and making it easy to clean.

In the resulting knife substantially all surfaces which in operation come in contact with the meat are rendered non-corrosive, so that they are not affected by the acids of the meat, by the coating of stainless steel applied over the arms of the core or base i 6, completely along them to and onto the hub portion If to any extent desired. The cutting and plate-engaging portions of the blades, being formed of the hard stainless steel, are extremely durable and in practice are found to stand up'over long periods of use without sharpening or other attention. The composite knife made in accordance with the method of my invention is superior to one formed entirely of stainless steel of similar quality and hardness, due to the comparative brittleness of said material. By providing in effect a base of the relatively soft but tough steel, by means of the core or forging i6, breakage of the blades is reduced to a minimum, the operating stresses and vibrations being largely absorbed by the comparatively soft steel core. At the same time a substantial saving is effected in the quantity of the relatively expensive stainless steel employed, as contrasted with forming a cutter entirely from such material.

My invention is not limited to the particular embodiment or steps as herein illustrated or described, its scope being pointed out in the following claims.

I claim:

1. The method of making a plural-bladed knife for a meat cutter, which comprises the steps of providing a forged blank or core element having a plurality of arms extending from a hub, applying along a corresponding side of each arm a stainless-steel rod having an angular corner portion adapted to constitute a cutting edge, fusing the material of said rods while preserving their edge-forming corner portions intact, and flowing said material onto and around the corresponding arm thereby to anchor said edge portions to the arms and to provide a non-corrosiv metallic coating for the latter.

2. The method of making a plural-bladed knife for a meat cutter, which comprises the steps of providing a forked blank or core element having a plurality of arms extending from a hub, applying along a corresponding side of each arm a stainless-steel rod having an angular corner portion adapted to constitute a cutting edge, fusing and flowing the rod material at one face of the blank so as to carry portions of said material adjacent the respective arms onto and about the surfaces of said arms at said face of the blank as a coating therefor, inverting the blank and similarly fusing and flowing the rod material onto the surfaces of the arms at the other face of the blank, so as to coat them substantially in their entirety, and in both said operations maintaining the angular edge-forming corner portions of the stainless-steel rods intact in their initial shape and condition.

3. The method of making a plural-bladed knife for a meat cutter, which comprises the steps of providing a core element of'relatively soft steel and having a plurality of arms extending from a hub, abutting stainless-steel rods having at least one longitudinal portion of angular form in section against corresponding faces 'of each arm of said core element and with said angular portions outermost, flowing the stainless steel of said rods completely around their abutted arms by a'fuse welding operation while keeping said angular portions intact to provide cutting edges, and grinding the resulting composite blades to provide the finished knife.

DONALD O. BECKNER.

CERTIFICATE OF CORREC'IPION. Patent No. 2,176,867. October ELL, 1959.

DONALD O. BECKNER.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, sec- 0nd column, line 56, claim 2, for the word "forked" read forged; and that t the said Letters Patent should'be read with this correction therein that the same may conform to the record of the case in the Patent Office..

Signed and sealed this 21st day of November, A. D. 1939.

4 Henry Van Arsdale, (Seal) Acting Commissioner of Patents. 

